Television having a java engine and a removable device port

ABSTRACT

Method and apparatus for use with televisions having an internal Java engine are included among the embodiments. In exemplary systems, a PCMCIA port allows the Java engine to load and execute Java applets selected by the viewer. Provision is made for system-aware applets to run concurrently with platform-independent applets on different Java display planes that are merged for display. Other embodiments are described and claimed.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

This application is a continuation of U.S. non-provisional patentapplication Ser. No. 10/868,591, filed Jun. 14, 2004, titled TELEVISIONHAVING A JAVA ENGINE AND A REMOVABLE DEVICE PORT, which claims priorityfrom U.S. provisional application Ser. No. 60/535,149 filed Jan. 6,2004, titled TELEVISION HAVING A JAVA ENGINE AND A REMOVABLE DEVICEPORT, all of which are incorporated by reference in its entirety.

FIELD OF THE INVENTION

This invention pertains generally to televisions, and more particularlyto televisions with the capability to run Java applications and appletsor similar routines.

BACKGROUND

Television receivers have long had the capability to create simple “OnScreen Display” (OSD) graphics that overlay a received video program.Such graphics can display video and audio settings for interactivetelevision adjustments, closed captioning, current channel/inputselections, etc. A simple graphics generator or television processorprovides the graphics in such systems.

Recently, television receivers such as the Sharp Aquos™ have beenintroduced with more sophisticated graphics capability that allows aricher menu experience. These graphics are programmed as a fixed routinethat is run by a television processor when the user selects a menufunction with a remote. The fixed routine is stored in a ROM at the timeof manufacture and called as needed based on viewer input, e.g., with aremote control.

Some computers have the capability to run Java applets in oneapplication window and display digital video (e.g. from a DVD-ROMinserted in an attached drive or Internet-streamed video) in anotherapplication window. Such a computer is not a “television” but amulti-tasking computer platform that can run video display software asmerely another graphical application controlled by the operating system.Current televisions do not have a capability for a viewer to select andrun different Java applets, and more specifically, have no provisionthat would allow a viewer to load and run applets on the television thatwere not part of the television at the time of manufacture.

BRIEF DESCRIPTION OF THE DRAWING

The embodiments may be best understood by reading the disclosure withreference to the drawing, wherein:

FIG. 1 contains a block diagram for a digital television according tosome embodiments of the present invention;

FIG. 2 shows the basic associations between display sources, displayplanes, and display plane mixing order according to some embodiments ofthe present invention;

FIG. 3 illustrates in block diagram form a mechanism formultiplexing/merging two graphics planes to a common television display,useful in some embodiments of the present invention;

FIG. 4 shows how active regions of a system display plane are noted in alinked list in some embodiments of the present invention;

FIG. 5 contains a flowchart indicating high-level control for softwaremixing of two Java display planes according to some embodiments of thepresent invention;

FIG. 6 contains a flowchart for low-level mixing of two Java displayplanes into a composite display according to some embodiments of thepresent invention;

FIG. 7 contains a flowchart for low-level updates of an anti-flickerdisplay buffer according to some embodiments of the present invention;and

FIGS. 8A-H depict display paths for an application manager and threeapplets as the application/applet focus changes between various sources,according to some embodiments of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

This description pertains to televisions with the capability to run Java(or similar) applets and display output from the Java applets to thetelevision display. Standard Java does not support multi-plane graphics,which can be highly desirable in a television where multipleconcurrently executing applets may be necessary and/or the system itselfmay need to create Java output.

As used herein, a television primarily functions to display video fromone or more external video sources. The television embodiments describedherein still retain this primary function, but have added capabilitiesto run applets that can create graphical output that overlays (orsupercedes) a video source. As televisions generally do not possess thevoluminous processing and storage resources of a computer, are expectedto fit in a clean form factor similar in size to the display itself, andpreferably are operable by persons with less technical expertise thancomputer users, using simpler interface devices, running applets on atelevision presents particular challenges that are addressed herein. Inparticular, newer LCD and plasma televisions tout their thinness andlightness as selling points, and thus have little room for the bulkyheat-generating components of a fast computer.

Conventional televisions offer a fixed set of pre-loaded graphicalapplications, typically limited to configuration menus for thetelevision. The embodiments below can include a richer set of pre-loadedapplets/applications, for instance voice messaging, timers, mediaplayers/recorders/time shifters and media locator/selectors, etc. Theembodiments also offer a viewer the capability to select otherapplets—not preloaded on the television—and run the applets on thetelevision. In addition to new or upgraded applets developedspecifically for the television platform (“platform-aware” applets), theembodiments preferably also allow a viewer to run applets that areplatform independent, such as games or other applets that are typicallyavailable to computer users. Because platform-independent applets arecurrently developed without use by a television viewer as a primaryconsideration, the television embodiments herein preferably allow suchapplets to run as expected, while still allowing the television tofunction as expected.

To allow a viewer to provide new applets to the television, thetelevision contains a removable device port, which supports media, aswell as other removable devices, In some embodiments, the removabledevice port comprises one or two PCMCIA (Personal Computer Memory CardInternational Association) PC card ports. The PC card and its ports aredescribed in a series of standards dating back to the 1980s—see, forinstance, PC Card Standard 8.0 Release—April 2001. The PC card interfacewas developed for laptop computers and other computers that do notprovide the large internal card bays (e.g., for Peripheral ComponentInterconnect cards) of desktop and tower servers. PC cards manufacturedtoday provide Ethernet network interfaces, modems, wireless networkinterfaces (e.g., IEEE 802.11x), mass storage with micro disk drives orflash memory (CompactFlash), and CompactFlash adapters for other flashformats such as Memory Stick, MultiMedia Card, Secure Digital,SmartMedia, and XD. In some embodiments, applets can be provided to thetelevision by loading the applets to a mass storage device, e.g., from acomputer, or purchasing a mass storage device with the appletspreloaded, and then connecting the mass storage device to the PC cardport. Alternately, with a wireless network interface card inserted inthe PCMCIA port, applets stored on a personal computer on the samewireless network can be accessed at the television. Additionally, thetelevision may accept and support other PCMCIA-compatible devices.

FIG. 1 contains a block diagram for a Liquid Crystal Display (LCD)television capable of operating according to some embodiments of thepresent invention. Television 100 contains an LCD panel 102 to displayvisual output to a viewer based on a display signal generated by an LCDpanel driver 104. LCD panel driver 104 accepts a primary digital videosignal in CCIR656 format (eight bits per pixel YC_(b)C_(r), in a “4:2:2”data ratio wherein two C_(b) and two C_(r) pixels are supplied for everyfour luminance pixels) from a digital video/graphics processor 120.

A television processor 106 provides basic control functions and viewerinput interfaces for television 100. Television processor 106 receivesviewer commands, both from buttons located on the television itself (TVcontrols) and from a handheld remote control unit (not shown) throughthe IR Port. Based on the viewer commands, television processor 106controls an analog tuner/input select section 108, and also suppliesuser inputs to the digital video/graphics processor 120 over a UniversalAsynchronous Receiver/Transmitter (UART) command channel. Televisionprocessor 106 is also capable of generating basic On-Screen Display(OSD) graphics, e.g., indicating which input is selected, the currentaudio volume setting, etc. Television processor 106 supplies these OSDgraphics, when activated, as a TV OSD signal to LCD panel driver 104 foroverlay on the display signal.

Analog tuner/input select section 108 allows television 100 to switchbetween various analog (or possibly digital) inputs for both video andaudio. Video inputs can include a radio frequency (RF) signal carryingstandard broadcast television, digital television, and/orhigh-definition television signals, NTSC video, S-Video, and/or RGBcomponent video inputs, although various embodiments may not accept eachof these signal types or may accept signals in other formats (such asPAL). The selected video input is converted to a digital data stream, DVIn, in CCIR656 format and supplied to a media processor 110.

Analog tuner/input select section 108 also selects an audio source,digitizes that source if necessary, and supplies that digitized sourceas Digital Audio In to an audio processor 114 and a multiplexer 130. Theaudio source can be selected—independent of the current video source—asthe audio channel(s) of a currently tuned RF television signal,stereophonic or monophonic audio connected to television 100 by audiojacks corresponding to a video input, or an internal microphone.

Media processor 110 and digital video/graphics processor 120 providevarious digital feature capabilities for television 100, as will beexplained further in the specific embodiments below. In someembodiments, processors 110 and 120 can be TMS320DM270 signalprocessors, available from Texas Instruments, Inc., Dallas, Tex. Digitalvideo/graphics processor 120 functions as a master processor, and mediaprocessor 110 functions as a slave processor. Media processor 110supplies digital video, either corresponding to DV In or to a decodedmedia stream from another source, to digital video/graphics processor120 over a DV transfer bus.

Media processor 110 performs MPEG (Motion Picture Expert Group) codingand decoding of digital media streams for television 100, as instructedby digital video/graphics processor 120. A 32-bit-wide data bus connectsmemory 112, e.g., two 16-bit-wide×1 M synchronous DRAM devices connectedin parallel, to processor 110. An audio processor 114 also connects tothis data bus to provide audio coding and decoding for media streamshandled by media processor 110.

Dotted line 116 divides the media processor subsystem from the hostprocessor subsystem. Media processor 110 cannot directly access thedevices on the right (host) side of dotted line 116. Digitalvideo/graphics processor 120 can access media processor 110 and memory112 directly, however, and thus indirectly provides connectivity betweenmedia processor 110 and flash memory 126 or PCMCIA cards 128.

Digital video/graphics processor 120 coordinates (and/or implements)many of the digital features of television 100. A 32-bit-wide data busconnects memory 122, e.g., two 16-bit-wide×1M synchronous DRAM devicesconnected in parallel, to processor 120. A 16-bit-wide system busconnects processor 120 to media processor 110, an audio processor 124,flash memory 126, and ports for removable PCMCIA cards 128. Flash memory126 stores boot code, configuration data, system executable code, andJava code/class files for graphics applications and applets, etc. PCMCIAcards 128 can provide extended media and/or application capability, suchas the Java applets explained herein.

Digital video/graphics processor 120 can pass data from the DV Transferbus to LCD panel driver 104 as is, but processor 120 can also supersede,modify, or superimpose the DV Transfer signal with other content. Forinstance, processor 120 can generate Java application/applet graphicsthat overlay or supercede the DV Transfer signal, system graphics thatdisplay messages over all underlying content, or decode media fromPCMCIA cards 128, e.g., in a “time-shifting” mode where media processor110 is coding a program to the PCMCIA card and processor 120 decodes anddisplays a time-shifted version of the same program, allowing the viewerto pause, rewind, or skip through the program.

Multiplexer 130 provides audio output to the television amplifier andline outputs (not shown) from one of three sources. The first source isthe current Digital Audio In stream from analog tuner/input selectsection 108. The second and third sources are the Digital Audio Outputsof audio processors 114 and 124. These two outputs are tied to the sameinput of multiplexer 130, since each audio processor is capable oftri-stating its output when it is not selected. In some embodiments,processors 114 and 124 can be TMS320VC5416 signal processors, availablefrom Texas Instruments, Inc., Dallas, Tex.

At system powerup, digital video/graphics processor 120 creates anexecutable image for itself in memory 122 and for media processor 110 inmemory 112. Flash memory 126 stores the elements of this image asdefault system code for processors 110, 114, 120, and 124. This codeincludes: a system manager, a Java engine, which may contain anycombination of a just-in-time Java compiler, a Java interpreter, orprecompiled Java code, and a Java manager that manages Java applets forprocessor 120; audio codecs for processors 114 and 124; and video codecsfor processors 110 and 120. The system manager provides low-levelfunctions for communication with the other devices attached to processor120, and communicates system events to the Java manager and otherprocesses. The Java engine interprets and executes Java code for theJava manager, and Java applets when applets are loaded.

Referring to FIG. 2, processor 120 works at various times with up tothree display planes: a system display plane 30, an applet display plane40, and a video and still image plane 50. The rearmost plane 50 cancontain digital video received at the DV Transfer port from processor110 or decoded MPEG video or JPEG images, as well as images originallystored in other formats. The middle plane 40 is active when a Javaapplet 95 has focus, or when the Java Manager displays graphics on themiddle plane. The front plane 30 is used, typically infrequently, todisplay alert and status messages from the Java manager. These messagescan include message requests from a platform-aware Java applet 90 thatdoes not have focus.

To create the digital video stream for the display, software mixer 200and hardware mixer 70 combine information from display planes 30, 40,and 50. Software mixer 200 combines information from display planes 30and 40, as will be explained in further detail below. A look-up table(LUT) is used in block 60 to convert the output of software mixer 200 tothe YC_(b)C_(r) color space of video plane 50. The output of LUT colorconversion block 60 is combined with video plane 50 in hardware mixer70.

FIG. 3 shows internal detail of software mixer 200. Applet planegraphics are rendered to applet display buffer 210. System planegraphics are rendered to system display buffer 220. Although it ispossible to merge graphics from these two planes in a fairly mindlessfashion for each video frame, display artifacts would be visible to aviewer from time to time, and a significant percentage of availableprocessing resources would be consumed merely to perform the merge.Mixer 200, however, takes advantage of the observations that systemgraphics are displayed a small percentage of the time and usually occupya small region of the viewable area to provide visually acceptablemixing while consuming far less resources.

The output of software mixer 200 is taken at a multiplexer 280.Multiplexer 280 can take input from one of three buffers: applet displaybuffer 210, system display buffer 220, or an anti-flicker display buffer270. The multiplexer select signal is generated by region manager 290,and the select criteria will be explained below. To summarize, however,if only one of the applet and system display planes is active, mixing isbypassed to save resources, and two switches 240 and 245 remain open.Only when both display planes are active are switches 240 and 245 closedto cause mixing to occur.

Further, even when both display planes 210 and 220 are active, mixing isonly performed as needed. Region manager 290 tracks which regions ofbuffers 210 and 220 are being updated, and controls a MUX control block230, a multiplexer 250, and the addressing of a composite display buffer260 and the anti-flicker display buffer 270 to mix only the updatedregions.

In order to intelligently control mixing, region manager 290 receivestwo types of notifications: system graphics section registration (andunregistration) notifications from the Java manager; and paint regionnotifications for both display buffers from the Java engine. The regionmanager 290 can be implemented, wholly or partly, within the Javaengine. Referring to FIG. 4, when the Java manager 300 desires to paintsystem graphics to a region of the display, it calls a Java engine API(Application Programming Interface) to register a rectangular section ofthe display bounding the desired region (the system graphics need not berectangular, but the registered section is preferably rectangular forsimplicity). For instance, FIG. 4 shows two registered section of thesystem display plane. Section 1 is described by the parameters (x1, y1,w1, h1), which respectively specify the section's left boundary withrespect to the left edge of the display, the section's upper boundarywith respect to the top edge of the display, the section's width, andthe section's height. Section 2 is described by similar parameters (x2,y2, w2, h2). A second API allows the Java manager to unregister apreviously registered section.

In some embodiments, region manager 290 maintains a linked list ofregistered system graphics areas, with the head of the list maintainedby a pointer SystemGraphics Section Head that is initially a NULLpointer. When the Java manager requests registration of section 1, anode is added to the linked list containing the parameters (x1, y1, w1,h1) and a Next pointer that is initially NULL. When the Java managersubsequently requests registration of section 2, a second node is addedto the linked list containing the parameters (x2, y2, w2, h2) and a Nextpointer that is initially NULL. The Next pointer of the first node ismodified to point to the second node to create the linked list shown inFIG. 4.

When the Java manager unregisters a region, the corresponding node isremoved from the linked list. Whenever SystemGraphics Section Head isnot NULL, region manager 290 assumes that system graphics are active.Note that region manager 290 can in some embodiments choose to merge twolinked list nodes to a single bounding rectangle node, particularly ifthe regions overlap.

The second type of notification received by region manager 290 is apaint region notification. Whenever an applet with focus or a componentof the Java manager calls a routine to draw to applet display buffer210, the draw or paint routine notifies region manager 290 that arectangular bounding region for the routine has been modified. Wheneverthe Java manager draws to system display buffer 220, the draw or paintroutine sends a similar notification to region manager 290. Regionmanager 290 uses paint region notifications to create a second linkedlist similar to the system graphics section linked list. As shown in theflowcharts of FIGS. 5-7, region manager 290 uses the paint region linkedlist to control mixing when both buffers 210 and 220 are active.

Returning briefly to FIG. 3, MUX control 230 controls the mixingoperation of multiplexer 250. MUX control 230 causes multiplexer 250 tooperate on the portions of buffers 210 and 220 that are newly added tothe paint region linked list. If a newly-painted section does notoverlap a current system graphics section, switch 245 is kept open andthe paint region is copied to the composite display buffer. When asystem graphics section is overlapped, mixing is required. In that case,MUX control 230 looks for a hard key in the pixel data coming out ofsystem display buffer 220: when the hard key is not set for a particularpixel, the current pixel in buffer 220 is copied to composite displaybuffer 260; when the hard key is set for a particular pixel, the currentpixel in buffer 210 is copied to composite display buffer 260. In someimplementations, the hard key is a pixel value of zero, which indicatesa transparent pixel.

FIG. 5 shows the high-level mixing control operation of region manager290. The output of mixer 280 depends on whether system graphics areenabled and whether an applet (or the Java manager) has focus. When bothof these conditions are false, region manager 290 disables hardwaremixing and multiplexer 280 need not produce any output. When systemgraphics are disabled but an applet has focus, the applet display buffer210 output is selected for hardware mixing with video. When systemgraphics are enabled and an applet does not have focus, the systemdisplay buffer 220 output is selected for hardware mixing with video.And when system graphics are enabled and an applet has focus, softwaremixing is required.

When software mixing is required, region manager 290 determines whetherthe status of the system display or applet display has changed since thelast time region manager 290 performed this analysis. In particular, ifmixing was not performed on the immediately preceding frames, theanti-flicker display buffer 270 likely is not current and should beinitialized before multiplexer 280 switches to accept output from buffer270. In this instance, region manager 290 sets the whole display area asan update region before initiating mixing.

During software mixing, the output of buffers 210 and 220 is mixed tocomposite display buffer as shown in FIG. 6, and the anti-flickerdisplay buffer is updated as shown in FIG. 7 from the composite displaybuffer on a frame interrupt to prevent frame tearing. Once theanti-flicker display buffer is stable, region manager 290 selects theanti-flicker display buffer for hardware mixing.

FIG. 6 shows the software mixing process. When no newly painted regionshave been added to the paint region linked list since the last mixingoperation, no software mixing is required and the routine returns.Otherwise, the first region in the paint region linked list is selected.Region manager 290 determines whether the paint region overlaps a systemregion in the system graphics section linked list: when the regionsoverlap, the output of buffers 210 and 220 are merged into compositedisplay buffer 260, as previously described, for the paint region; whenthe paint region does not overlap any registered system region, thecorresponding region of applet display buffer 210 is copied to compositedisplay buffer 260.

Once the composite display buffer has been updated for a paint region,the corresponding node in the paint region linked list is modified toindicate a status of “mixed.” Region manager 290 then traverses to thenext node in the paint region linked list. When the next region is NULL,the end of the list has been reached and the software mixing routineexits. When the next paint region is not NULL and has not been mixedalready, the software mixer loops back up and processes the new regionas described for the first region.

FIG. 7 shows the anti-flicker display buffer update process. Preferably,an anti-flicker display buffer update routine is called on frameinterrupt so that updates are synchronized with the display sequencing.Region manager 290 determines whether any paint regions in the paintregion linked list have been marked as “mixed.” When no newly mixedregions have been added to the paint region linked list since the lastmixing operation, no anti-flicker display buffer updates are requiredand the routine returns. Otherwise, the first region in the paint regionlinked list is selected. Region manager 290 determines whether the firstpaint region has been mixed yet to the composite display buffer; when ithas, the region is copied from the composite display buffer to theanti-flicker display buffer and the region is removed from the paintregion linked list. When the first paint region has not yet been mixed,processing is bypassed for that region.

Region manager 290 then traverses to the next node in the paint regionlinked list. When the next region is NULL, the end of the list has beenreached and the anti-flicker display buffer routine exits. When the nextpaint region is not NULL, the routine loops back up and processes thenew region as described for the first region.

The Java engine allows multiple Java applets to run concurrently witheach other and with the Java manager. As just described, however, onlyone applet at a time can have the “focus” of the viewer's remote controlor other input device and perform updates to the applet display buffer.Platform-aware applets can be written to understand what it means toreceive and lose focus, but no such assumption can be made when theviewer is allowed to load platform-independent Java applets from thePCMCIA port. Thus the television embodiments are designed to cope withtwo types of Java applets: platform-aware applets, which are codedspecifically to interoperate with the Java manager and platform-specificAPIs, and platform-independent applets, which are not. Generally, theapplets that are factory-loaded into flash memory 126 are platform-awareapplets, while applets accessible through PCMCIA cards can be eitherplatform-aware applets or platform-independent applets. Platform-awareapplets have access to platform-specific APIs to perform such functionsas channel and volume changes, picture-in-picture functions, JPEG andMPEG4 display, etc.

The Java manager includes a class (the application manager) thatfunctions as a Java applet browser/launcher. The application manager canbe assigned to a specific key on the viewer's remote control and/or canbe activated from a menu. The application manager maintains a list ofcurrently-available Java applets that are available to the viewer. Thislist will typically include some of the Java applets stored in flashmemory 126 (some may only be available to other Java applets and not tothe viewer) and any applets found using PCMCIA cards 128. Preferably,the application manager locates descriptor files and icons for eachavailable applet and can then present the applets to a viewer in aneasily-comprehended graphical format. Note that if a PCMCIA card 128provides wireless connectivity to multiple “shares,” where a share is ashared resource located on a computer or other wireless device, appletsavailable on each share can be arranged in the graphical format byshare.

Assume for the following example that the application manager 310 is thedescribed application manager and a platform-aware applet B 320 is anMP3 player. In addition, assume that the application manager has locatedtwo platform-independent applets, an applet C 330 and an applet D 340,which could be for instance a solitaire game and a checkers game,respectively. FIGS. 8A-8H illustrate applet/manager function as a viewernavigates between the application manager, these various applets, andthe video function of the television. An applet that is currently notloaded to memory 122 is depicted with a dashed border; an applet that isloaded to memory 122 is depicted with a solid border; and an applet thathas focus is depicted with a bold solid border.

In FIG. 8A, the viewer selects application manager 310 from a remotecontrol. The Java manager 300 is notified of the viewer selection anddirects focus to the application manager class. The Java engine isnotified that the application manager class will now receive focus andreceives a request to begin executing the class files for theapplication manager if they were not executing already. The applicationmanager locates the applets available to the viewer in flash memory andthrough a PCMCIA card and creates a browse/launch display in appletdisplay buffer 210. The viewer may then use remote control buttons tonavigate and select one of the displayed applets, with the applicationmanager modifying its display according to the navigation commands inorder to interact with the viewer.

When a user selects one of the displayed applets, the applicationmanager notifies Java manager 300 that the viewer has requested thelaunch of an applet. For instance, in FIG. 8B, the viewer selects appletB, the MP3 player. The Java manager 300 calls the Java engine to launchapplet B. Application manager 310 loses focus and can no longer paint tothe applet display buffer. The Java engine is notified that applet Bwill now receive focus and receives a request to begin executing theclass files for the MP3 player. Applet B may provide to the viewer, forinstance, playlists or individual MP3 file lists for MP3 filesaccessible through the PCMCIA cards 128. The viewer may then use remotecontrol buttons to navigate and select an MP3 file, files, or playlistand hit “play” to begin playing the selected MP3 media through audioprocessor 124.

Although the application manager has now lost focus, it still runs in abackground mode. When a new PCMCIA card is inserted or removed from thetelevision, or new shares appear or disappear from the wireless LAN, theapplication manager can be programmed to notify the viewer that the listof available applets has changed. For instance, on PCMCTA card removal,all running processes receive a broadcast message that the card has beenremoved. Upon receiving this message, since the application manager doesnot have focus, it can signal another section of the Java manager torequest a transient system message, e.g., “Some Applets No LongerAvailable—Press Applets Key to View Current List”. Java manager 300requests a system graphics section for the message and displays it tosystem display buffer 220.

Referring now to FIG. 8C, the viewer now selects a Video mode, causingapplet B to lose focus. Java manager 300 asks applet B whether it can bekilled. In this example, applet B responds “no,” at which time applet Bis notified that it has lost focus and can no longer paint to the appletdisplay buffer. The Java engine is notified that applet B has lostfocus, but applet B can continue to play MP3 files in a background mode.Like the application manager, applet B can use the Java manager todisplay status messages, such as a song name when a new song starts, onthe system display buffer.

In FIG. 8D, the viewer presses a button to return focus to theapplication manager. The Java engine is notified that the applicationmanager now has focus, the application manager is notified that it hasfocus, and the application manager once again draws its applet browserdisplay to applet display buffer 210.

In FIG. 8E, the viewer selects a platform-independent applet C (thesolitaire game) and launches it, causing a series of events similar tothose described for FIG. 8B. The solitaire game class files are loadedfrom the PCMCIA card to memory 122 and applet C is launched. Whereasapplet B registered as a platform-aware applet when launched, applet Chas no such registration function, and thus the Java manager 300 andJava engine know that applet C has no internal provision for receivingand losing focus. Applet C output is directed to the applet displaybuffer and the viewer can operate the applet using remote controlbuttons. Since the applet display buffer requires no special APIcontrols, platform-independent applets can write to it without problem.The Java engine and software mixer allow the platform-independentapplets to function in a manner that is compatible with the televisionplatform.

In FIG. 8F, the viewer once again selects the application manager toregain focus. Applet C cannot continue to run because it does not havethe ability to direct its output anywhere but the applet display buffer,and thus would interfere with the output of the application manager.Applet C can either be killed or “paused,” i.e. remain in memory but notreceive any calls, as a design choice. If paused, applet C canpotentially be resumed by reselecting it from the application manager.The kill or pause decision can also be based on other criteria, such asmemory usage. Thus if memory usage is high, the oldest “paused” appletscan be deleted from memory.

FIG. 8G illustrates a case where the viewer selects a differentplatform-independent applet D to run. Before applet D class files areloaded, applet C can be killed to free memory, and then applet D can belaunched and run in similar fashion to applet C.

Finally, in FIG. 8H the viewer once again selects a Video mode, causingthe Java manager to pause (or optionally kill) applet D.

Although optional, the application manager could allow otherapplet-related activities. For instance, applets could be copied from anetwork share to PCMCIA mass memory. Or, a “favorite applet” could bedesignated and saved to flash memory 126.

One of ordinary skill in the art will recognize that the concepts taughtherein can be tailored to a particular application in many otheradvantageous ways. In particular, those skilled in the art willrecognize that the illustrated embodiments are selected from manyalternative implementations that will become apparent upon reading thisdisclosure. The particular functional block groupings used hereinpresent one possible functional grouping, but functions can besubdivided and/or combined in many other combinations that fall withinthe scope of the appended claims. Although Java applets have beendescribed, the described embodiments can be used with otherobject-oriented coding schemes.

The removable device port can be a port other than a PCMCIA port. Forinstance, a Firewire (IEEE 1394) or USB (Universal Serial Bus) 2.0 portcan be used to connect a removable device. Ports that directly acceptMemory Stick, MultiMedia Card, Secure Digital, SmartMedia, and/or XDflash devices can also be used.

Two Java buffers have been described, but more can exist and beintegrated into the described mixing schemes. Mixing with a single hardkey has been described, but more complicated mixing schemes arepossible. Such minor modifications are encompassed within theembodiments of the invention, and are intended to fall within the scopeof the claims.

The preceding embodiments are exemplary. Although the specification mayrefer to “an”, “one”, “another”, or “some” embodiment(s) in severallocations, this does not necessarily mean that each such reference is tothe same embodiment(s), or that the feature only applies to a singleembodiment.

1. A television comprising: at least one video input; a programmableprocessor to supply a digital video stream for a television display, thedigital video stream based on the video input in at least oneoperational mode; a removable-device port coupled to the programmableprocessor; and an execution engine capable of launching executable codeaccessible through the removable-device port when a removable device isinserted in the removable-device port; wherein the programmableprocessor is capable of directing the output of the executable codeaccessed through the removable-device port to the digital video stream;and wherein the execution engine runs a manager application that can runconcurrently with the executable code, the manager application directinggraphical output to a system display plane and the executable codedirecting graphical output to an executable code display plane.
 2. Thetelevision of claim 1, further comprising a digital video input to theprogrammable processor, the processor having the capability to mergeoutput from the executable code with digital video received at thedigital video input to create the digital video stream.
 3. Thetelevision of claim 1, wherein the programmable processor merges thesystem display plane and the executable code display plane to create thedigital video stream.
 4. The television of claim 1, wherein theexecutable code accessed through the removable-device port isplatform-independent, the television further comprising platform-awareexecutable code capable of concurrent execution with theplatform-independent executable code.
 5. The television of claim 4,wherein the platform-aware executable code is capable of directinggraphical output at either the system display plane or the executablecode display plane, as instructed by the manager application.
 6. Thetelevision of claim 1, further comprising a non-volatile memory coupledto the programmable processor, wherein the programmable processor iscapable of transferring the executable code from the removable-deviceport to the non-volatile memory.
 7. The television of claim 1, furthercomprising a memory coupled to the programmable processor, wherein theprogrammable processor loads the executable code from theremovable-device port to the memory, and executes the executable codefrom the memory.
 8. The television of claim 7, further comprising ajust-in-time compiler to compile the executable code prior to execution.9. The television of claim 1, wherein the removable-device port containsany one or more ports from the group of port types consisting of aPersonal Computer Memory Card International Association (PCMCIA) PC cardport, a Universal Serial Bus port, a Firewire port, and a flash memorydevice port.
 10. The television of claim 1, further comprising theremovable device, wherein the removable device provides access to theexecutable code located on a memory device integral to the removabledevice.
 11. The television of claim 1, further comprising the removabledevice, wherein the removable device provides access to the executablecode via a wireless connection to a remote device storing the executablecode.
 12. The television of claim 1, wherein the execution engine is aJava engine and the executable code comprises Java applets.
 13. Thetelevision of claim 1, wherein the execution engine is capable oflaunching both platform-aware and platform-independent executable codeaccessible through the removable-device port when the removable deviceis inserted in the removable-device port.
 14. A method of operating atelevision, the method comprising: providing a television port thatallows a viewer to connect a removable device to the television;accessing the removable device connected to the television port toobtain computer instructions; running the computer instructions;directing an output of the computer instructions to a televisiondisplay; and running a manager application that controls loading andexecution of the computer instructions, wherein the manager applicationis capable of loading and executing both platform-aware andplatform-independent computer instructions; wherein the managerapplication is capable of concurrent execution of first and second setsof computer instructions when at least the first set of computerinstructions are platform-aware computer instructions, the methodfurther comprising: directing the output of the first set of computerinstructions to a system display plane; directing the output of thesecond set of computer instructions to a second display plane; andmerging the output of the system and second display planes to form theoutput directed to the television display.
 15. The method of claim 14,further comprising the computer instructions identifying itself asplatform-aware computer instructions when the computer instructions areplatform-aware computer instructions.
 16. The method of claim 14,further comprising: instructing the first set of computer instructionsas to whether it is directing its output to the system display plane orthe second display plane; and the first set of computer instructionsmodifying its output according to the plane that is currently receivingthe output from the first set of computer instructions.
 17. The methodof claim 14, further comprising copying the computer instructions fromthe removable device to a system memory device and executing thecomputer instructions from the system memory device.
 18. The method ofclaim 17, further comprising compiling the computer instructions to thesystem memory device.
 19. A method of operating a television, the methodcomprising: running a manager application that controls loading andexecution of computer code, wherein the manager application is capableof loading and executing both platform-aware and platform-independentcomputer code; wherein the manager application is capable of concurrentexecution of first and second sets of computer code when at least thefirst set of computer code is platform-aware computer code, the methodfurther comprising: directing an output of the first set of computercode to a system display plane; directing an output of the second set ofcomputer code to a second display plane; and merging the output of thesystem and second display planes to form an output directed to atelevision display.
 20. The method of claim 19, further comprising thefirst set of computer code modifying its output depending on whetherthat output is directed to the system display plane or the seconddisplay plane.